JP2016016733A - In-wheel motor drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a cruising distance, and to improve a rated output by improving the cooling performance of an in-wheel motor drive unit by a lubricant.SOLUTION: An in-wheel motor drive unit 21 comprises: a motor part A which generates a drive force; a reduction gear B which decelerates the rotation of the motor part, and outputs it; and a wheel hub C which transmits the output from the reduction gear B to a drive wheel. The motor part A and the reduction gear B are accommodated in a casing 21, an oil feed passage 43 in which a lubricant circulates by an oil pump 42 is formed in the casing 21, the lubricant circulating in the oil feed passage 43 is guided to the motor part A and the reduction gear B, and the lubrication and cooling of the motor part A and the reduction gear B are performed. A groove or a protrusion is formed in the oil feed passage 43, a flow passage internal surface area of the oil feed passage 43 is increased, and the cooling efficiency of the lubricant from the oil feed passage is enhanced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an in-wheel motor drive device, and more particularly to a lubrication structure for an in-wheel motor drive device.

  As shown in FIG. 11, the in-wheel motor drive device 121 includes a motor part A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the motor part A, and an output from the speed reducer B as driving wheels. And a wheel hub C to be transmitted to the vehicle.

  The motor part A and the speed reducer B are accommodated in the casing 122. The casing 122 is partitioned by a partition wall 122c into a casing 122a on the motor part A side and a casing 122b on the reduction gear B side.

  The motor part A uses a radial gap type of which a stator 123 is provided on the inner peripheral surface of the casing 122a and a rotor 124 is provided at an interval on the inner periphery of the stator 123.

  The rotor 124 has a motor shaft 124a in the center. The motor shaft 124a is connected to the input shaft 130 of the speed reducer B and is inserted into the casing 122b of the speed reducer B. The bearings 125a and 125b are used for the casing 122a. And is supported rotatably.

  The casing 122b of the speed reducer B is provided with an oil tank 141 for lubricating oil at the lower portion. The lubricating oil in the oil tank 141 is sucked by the oil pump 142, and the lubricating oil is supplied to the motor unit A and the speed reducer B for lubrication. And cooling (Patent Documents 1 to 3).

  The oil supply passage 143 that supplies the lubricating oil to the inside of the motor unit A and the speed reducer B is connected to the casing 122a from the discharge port of the oil pump 142 that is driven by using the output rotation of the speed reducer B that reduces the rotation of the motor unit A. An outer diameter passage 143a extending rearward along the inside of the outer diameter portion, a rear cover passage 143b provided in the rear cover 122d, an inner passage 144 of the motor shaft 124a, and an input shaft 130 of the speed reducer B. A passage that extends through the internal passage 145 into the casing 122 b of the reduction gear B and a suction passage 146 that extends from the oil tank 141 to the suction port of the oil pump 142 are configured. The cross-sectional shape of the oil supply passage 143 is formed in a circular cross section as shown in FIG.

  The lubricating oil supplied from the oil pump 142 is guided into the casing 122a on the motor part A side from the radial oil hole 144a provided in the internal passage 144 of the motor shaft 124a, and lubrication and cooling of the motor part A are performed. Then, the oil tank 141 is discharged from below the casing 122a on the motor part A side.

  In addition, oil holes 145a and 145b are also provided in the radial direction in the internal passage 145 of the input shaft 130 of the speed reducer B. Lubricating oil scatters from the oil holes 145a and 145b by centrifugal force to lubricate and reduce the inside of the speed reducer B. It is cooling. That is, a so-called axial oil supply system is adopted.

  The return path for the lubricating oil is constituted by a discharge port 147 provided at the bottom of the casing 122 b of the speed reducer B and an oil tank 141.

JP 2011-077944 A Japanese Patent Laid-Open No. 2005-199828 JP 2013-063727 A

  Cooling with the lubricating oil greatly affects the performance of the in-wheel motor drive device 121.

  For example, when the temperature of the motor part A rises, there is a risk of output reduction due to demagnetization of the magnet, early deterioration of the insulator, and damage to each part including the rotor support bearing. In particular, in the case of an electric vehicle, there is a limit on the battery capacity side, but in order to increase the cruising distance and improve the rated output (output that can continue to rotate for a specified time), increase the oil temperature of the motor part A. It is important to suppress. Also, if the temperature of the reduction gear B rises, there is a risk of seizure of the rolling parts and damage of each part, and the lubricating oil itself deteriorates and the lubricating performance is lowered.

  By the way, in order to enhance the cooling effect by the lubricating oil, it is necessary to cool the lubricating oil itself that passes through the oil supply passage 143.

  A plurality of fins 150 are provided on the outer peripheral surface of the casing 122a on the motor part A side, the outer peripheral surface of the casing 122b of the speed reducer B, and the outer diameter surface of the rear cover 122d, and the fins 150 are cooled by traveling wind or the like. As a result, the temperature of the casing 122 decreases, and the lubricating oil passing through the oil supply passage 143 provided in the casing 122 is cooled.

  As described above, the lubricating oil is cooled by heat conduction to the casing 122 when passing through the oil supply passage 143. The amount Q of heat conduction from the lubricating oil to the casing 122 increases as the flow rate of the lubricating oil and the flow path surface area increase. The flow rate of the lubricating oil depends on the flow path cross-sectional area.

  Therefore, in order to enhance the cooling effect of the lubricating oil, it is effective to increase the flow passage surface area S by extending the lubricating oil supply passage.

  However, extending the lubrication oil supply passage provided in the casing 122 has a concern that the shape of the lubrication passage may become complicated, or that the cost may increase due to an increase in the number of processing steps, and the amount of lubrication oil increases due to the extension of the oil supply passage. There are also concerns about pressure loss.

  Therefore, the present invention increases the flow passage surface area of the oil supply passage with almost no change in the length of the oil supply passage, and under the condition that the flow velocity of the lubricating oil and the flow passage cross-sectional area of the oil supply passage are substantially constant. The cooling effect of the lubricating oil from the oil supply passage is to be enhanced.

  In order to solve the above problems, in the present invention, a motor unit that generates a driving force, a speed reducer that decelerates and outputs the rotation of the motor unit, and a wheel hub that transmits the output from the speed reducer to the drive wheels. The motor part and the speed reducer are accommodated in a casing, and an oil supply passage through which lubricating oil circulates by an oil pump is provided in the casing, and the lubricating oil circulated through the oil supply path is guided to the motor part and the speed reducer, In the in-wheel motor drive device that performs lubrication and cooling of the motor unit and the speed reducer, a groove or a protrusion is provided in the oil supply passage to increase the surface area in the flow passage of the oil supply passage.

  It is preferable that the groove or the protrusion is provided in parallel with the flow path of the oil supply passage.

  A plurality of the grooves or protrusions may be provided in the flow path of the oil supply passage.

  In the in-wheel motor drive device according to the present invention, as described above, since the groove or protrusion is provided in the oil supply passage to increase the surface area in the flow passage of the oil supply passage, the length of the oil supply passage is almost changed. In addition, the cooling effect of the lubricating oil from the oil supply passage can be enhanced even under conditions where the flow velocity v of the lubricating oil and the flow passage cross-sectional area A of the oil supply passage are substantially constant.

It is a vertical front view of the in-wheel motor drive device concerning this invention. It is an expansion vertical front view of a reduction gear. It is a vertical side view along the III-III line of FIG. It is an enlarged view of an oil pump. (A)-(f) is an example of the groove | channel or protrusion provided in the flow path of an oil supply path. It is a perspective view which shows an example which forms an oil supply channel | path in a rear cover. It is a perspective view which shows the example which forms an oil supply path in the outer diameter part of the casing which accommodates a motor part. It is a perspective view which shows the other example which forms an oil supply path in the outer diameter part of the casing which accommodates a motor part. It is a schematic plan view of the electric vehicle which has the in-wheel motor drive device of FIG. It is the figure which looked at the electric vehicle of FIG. 9 from back. It is a vertical front view which shows a prior art example. It is sectional drawing of the oil supply channel | path of a prior art example.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 9, an electric vehicle 11 including an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, front wheels 13 as steering wheels, drive wheels (rear wheels) 14, left and right And an in-wheel motor drive device 21 that transmits a drive force to each of the drive wheels 14. As shown in FIG. 10, the drive wheel 14 is accommodated in a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b. As a mounting form of the in-wheel motor drive device 21, any of a front wheel drive system and a four wheel drive system may be used in addition to the rear wheel drive system shown in FIGS.

  The suspension device 12b supports the drive wheel 14 by a suspension arm that extends to the left and right, and suppresses vibration of the chassis 12 by absorbing vibration received by the drive wheel 14 from the ground by a strut including a coil spring and a shock absorber. Furthermore, a stabilizer that suppresses the inclination of the vehicle body when turning or the like is provided at a connecting portion of the left and right suspension arms. The suspension device 12b is an independent suspension type in which the left and right wheels can be moved up and down independently in order to improve the followability to the road surface unevenness and efficiently transmit the driving force of the driving wheels to the road surface. Is desirable.

  The electric vehicle 11 needs to be provided with a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12 by providing an in-wheel motor drive device 21 that drives the left and right drive wheels 14 inside the wheel housing 12a. This eliminates the need to secure a wide cabin space and control the rotation of the left and right drive wheels.

  As shown in FIG. 1, the in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the motor unit A, and an output from the speed reducer B as driving wheels. The motor part A and the speed reducer B are housed in the casing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The motor part A and the speed reducer B are accommodated in the casing 22. The casing 22 is partitioned by a partition wall 22c into a casing 22a on the motor part A side and a casing 22b on the reduction gear B side, and a through-hole through which the motor shaft 24a of the motor part A is inserted is at the center of the partition wall 22c. Is formed.

  The motor part A uses a radial gap type in which a stator 23 is provided on the inner peripheral surface of the casing 22a, and a rotor 24 is provided at an interval on the inner periphery of the stator 23.

  The rotor 24 has a motor shaft 24a at the center, and the motor shaft 24a is connected to the input shaft 30 of the speed reducer B and is inserted into the casing 22b of the speed reducer B. And is supported rotatably.

  The casing 22b of the speed reducer B is provided with an oil tank 41 for lubricating oil at the lower portion, the lubricating oil in the oil tank 41 is sucked by the oil pump 42, and the lubricating oil is supplied to the motor unit A and the speed reducing device B for lubrication. And cooling.

  The oil supply passage 43 for supplying the lubricating oil to the inside of the motor unit A and the speed reducer B is connected to the casing 22a from the discharge port of the oil pump 42 that is driven by using the output rotation of the speed reducer B that decelerates the rotation of the motor unit A. An outer diameter passage 43a extending rearward along the inner side of the casing, a rear cover passage 43b provided in the rear cover 22d on the rear surface of the casing 22a, an internal passage 44 of the motor shaft 24a, and an input shaft 30 of the speed reducer B. And a suction passage 46 that extends from the oil tank 41 to the suction port of the oil pump 42 through the internal passage 45.

  The lubricating oil supplied from the oil pump 42 is guided into the casing 22a on the motor part A side from the radial oil hole 44a provided in the internal passage 44 of the motor shaft 24a, and lubricates and cools the motor part A. Then, the oil tank 41 is discharged from below the casing 22a on the motor part A side.

  Further, oil holes 45a and 45b are also provided in the internal passage 45 of the input shaft 30 of the speed reducer B in the radial direction. Lubricating oil is scattered from the oil holes 45a and 45b by centrifugal force to lubricate and reduce the inside of the speed reducer B. It is cooling. That is, a so-called axial oil supply system is adopted.

  The return path for the lubricating oil is configured by a discharge port 47 provided at the bottom of the casing 22 b of the speed reducer B and the oil tank 41.

  As shown in FIG. 4, the oil pump 42 includes an inner rotor 72 that rotates using the rotation of the speed reducer B, an outer rotor 73 that rotates following the rotation of the inner rotor 72, a pump chamber 74, and a suction chamber. The cycloid pump includes a suction port 75 communicating with the passage 46 and a discharge port 76 communicating with the oil supply passage 43.

  Inner rotor 72 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 72a is an epicycloid curve, and the shape of the tooth gap portion 72b is a hypocycloid curve. The inner rotor 72 rotates integrally with the output shaft 33 of the speed reducer B.

  The outer rotor 73 has a tooth profile formed of a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 73a is a hypocycloid curve, and the shape of the tooth gap portion 73b is an epicycloid curve. The outer rotor 73 is rotatably supported by the pump case 77.

  The inner rotor 72 rotates around the rotation center c1. On the other hand, the outer rotor 73 rotates around a rotation center c2 different from the rotation center c1 of the inner rotor. Further, when the number of teeth of the inner rotor 72 is n, the number of teeth of the outer rotor 73 is (n + 1). In this embodiment, n = 5.

  A plurality of pump chambers 74 are provided in the space between the inner rotor 72 and the outer rotor 73. When the inner rotor 72 rotates using the rotation of the output shaft 33 of the speed reducer B, the outer rotor 73 rotates in a driven manner. At this time, since the inner rotor 72 and the outer rotor 73 rotate around different rotation centers c1 and c2, the volume of the pump chamber 74 continuously changes. As a result, the lubricating oil flowing in from the suction port 75 is pumped from the discharge port 76 to the oil supply passage 43.

  As shown in FIG. 1, the casing 22 b of the speed reducer B is provided with an oil tank 41 for lubricating oil at the lower portion. The lubricating oil in the oil tank 41 is sucked by the oil pump 42 through the suction passage 46, and the motor unit A Lubricating oil is supplied to the reduction gear B to perform lubrication and cooling.

  As shown in FIGS. 1 to 3, the cycloid type speed reducer B rotatably supports two curved plates 31 by eccentric shaft portions 30 a and 30 b provided on the input shaft 30, and these curved plates 31. The corrugated tooth profile 31a formed on the outer periphery of the gear plate is engaged with the outer pin 32 disposed inside the casing 22b of the speed reducer B, and the curved plate 31 is caused to eccentrically swing by the rotation of the input shaft 30. The rotation of 31 is output from the output shaft 33 arranged coaxially with the input shaft 30, and the wheel hub C is rotated.

  The number of outer pins 32 disposed inside the casing 22 b of the reduction gear B is larger than the corrugated tooth profile 31 a on the outer periphery of the curved plate 31.

  As shown in FIG. 2, the outer pin 32 is supported by an outer pin housing 50 located on the inner diameter surface of the casing 22 b of the speed reducer B via a gap. The outer pin housing 50 is floatingly supported by floating bolts 59 on the outer side and the inner side with respect to the casing 22b of the speed reducer B.

  As shown in FIG. 1, one end of the input shaft 30 is connected to the motor shaft 24a of the rotor 24 by spline fitting and is driven to rotate by the motor portion A. The other end is an eccentric shaft. Portions 30a and 30b are provided.

  As shown in FIG. 2, a pair of eccentric shaft portions 30 a and 30 b are provided in the axial direction of the input shaft 30. The pair of eccentric shaft portions 30a and 30b is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and rolls to the outer diameter surface of each of the pair of eccentric shaft portions 30a and 30b. A bearing 34 is fitted.

  The eccentric shaft portions 30a and 30b are provided with oil holes 45a and 45b, and the lubricating oil passing through the internal passage 45 of the input shaft 30 is scattered from the oil holes 45a and 45b, and the rolling surfaces and sliding surfaces of the respective portions are formed. Lubricate.

  The input shaft 30 provided with the pair of eccentric shaft portions 30a and 30b is provided with a pair of counterweights 35 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 30a and 30b.

  The curved plate 31 is rotatably supported on the input shaft 30 by the rolling bearing 34, and the corrugated tooth profile 31a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 3, the curved plate 31 has a plurality of pin holes 36 formed at equal intervals on a single circle centered on the rotation axis, and each of the pair of pin holes 36 aligned in the axial direction is formed inside each of the pin holes 36. The pin 37 is inserted with a margin, and a part of the outer periphery of the roller bearing 37 a rotatably supported by the inner pin 37 is in contact with a part of the inner periphery of the pin hole 36.

  As shown in FIG. 2, the speed reducer B is engaged with two curved plates 31 as revolving members that are rotatably held by the eccentric shaft portions 30 a and 30 b, and a corrugated tooth profile 31 a on the outer peripheral portion of the curved plate 31. A plurality of outer pins 32, an output shaft 33 that outputs the rotation of the curved plate 31, and a gap between the two curved plates 31, abutting against the end surfaces of the curved plates 31 to tilt the curved plate 31. And a center collar 38 to prevent.

  As shown in FIG. 1, the output shaft 33 has a flange portion 33a and a shaft portion 33b. Inner pins 37 are fixed to the flange portion 33 a at equal intervals on a circumference centered on the rotation axis of the output shaft 33. As shown in FIG. 1, a wheel hub C is provided on the outer diameter surface of the shaft portion 33b so that torque can be transmitted by serrations (or splines). As shown in FIG. 2, the flange portion 33a and the stabilizer 33d are connected via a plurality of inner pins 37, and the output shaft 33 and the stabilizer 33d rotate integrally. A pump drive shaft 33c connected to the inner rotor 72 of the oil pump 42 is provided at the end of the stabilizer 33d on the motor part A side.

  The outer pins 32 are provided at equal intervals on the circumferential track of the rotation axis of the input shaft 30. When the curved plate 31 revolves, the outer peripheral corrugated tooth profile 31a and the outer pin 32 engage with each other, causing the curved plate 31 to rotate.

  As shown in FIG. 2, an output shaft 33 and a stabilizer 33 d are rotatably supported via a rolling bearing 90 on the inner periphery of the flange portion 51 of the outer pin housing 50. Further, the inner diameter surface of the flange portion 33 a and the stabilizer 33 d of the output shaft 33 and the outer diameter surface of the input shaft 30 are supported through a rolling bearing 91 so as to be relatively rotatable.

  The curved plate 31 is incorporated between the flange portion 33a and the stabilizer 33d facing the output shaft 33. Further, both ends of the inner pin 37 penetrating the pin hole 36 of the incorporated curved plate 31 are supported by the opposing flange portion 33a and the stabilizer 33d of the output shaft 33.

  The plurality of inner pins 37 supported by the flange portion 33 a and the stabilizer 33 d that face the output shaft 33 are provided at equal intervals on a circumferential track centering on the rotational axis of the input shaft 30, and friction with the curved plate 31. In order to reduce the resistance, needle roller bearings 37a are provided at positions where they contact the inner wall surfaces of the pin holes 36 of the two curved plates 31. The inner diameter dimension of the pin hole 36 is set to be larger than the outer diameter dimension of the inner pin 37 (referred to as “maximum outer diameter including the needle roller bearing 37a”; the same applies hereinafter).

  As shown in FIG. 1, the wheel hub C includes an inner ring member 81 fitted and connected to the outer diameter surface of the shaft portion 33 b of the output shaft 33 in a state where torque can be transmitted by serration (or spline), and the inner ring member 81. And an outer ring member 82 that is rotatably held with respect to the casing 22b. The inner ring member 81 and the outer ring member 82 constitute a double-row angular ball bearing, and a double-row rolling element 83 is installed between the inner ring member 81 and the outer ring member 82. The inner ring member 81 is integrally provided with a wheel mounting flange portion 84.

  The outer pin 32 is not directly held by the casing 22b, but is held by an outer pin housing 50 supported in a floating state on the inner diameter surface of the casing 22b, as shown in FIGS.

  In the in-wheel motor drive device 21, from the viewpoint of weight reduction, the casing 22 is preferably made of a light metal such as an aluminum alloy or a magnesium alloy, and the outer pin housing 50 that requires high strength is preferably made of steel.

  Further, in the lubrication of the cycloid reduction gear B, the lubricating oil supplied from the oil pump 42 passes through the internal passage 45 of the input shaft 30 and scatters from the oil holes 45a and 45b provided in the eccentric shaft portions 30a and 30b. The lubricating oil accumulated in the outer pin housing 50 is picked up by the rotation of the curved plate 31 and becomes splashed to lubricate the rolling surface and sliding surface of each part. The lubricating oil is lubricated and cooled in the reduction gear B, and then discharged to the oil tank 41 from the discharge port 47 below the casing 22b of the reduction gear B.

  The lubricating oil is cooled by heat conduction to the casing 22 when passing through the oil supply passage 43.

A plurality of fins 62 are provided on the outer peripheral surface of the casing 22a on the motor part A side, the outer peripheral surface of the casing 122b of the reduction gear B, and the outer diameter surface of the rear cover 22d, and the fins 62 are cooled by traveling wind or the like. As a result, the temperature of the casing 22 decreases, and the lubricating oil passing through the oil supply passage 43 provided in the casing 22 is cooled.
The amount Q of heat conduction from the lubricating oil to the casing 22 increases as the flow velocity of the lubricating oil and the flow path surface area increase. The flow rate of the lubricating oil depends on the flow path cross-sectional area.

  In the present invention, the cooling effect of the lubricating oil from the oil supply passage 43 is enhanced without changing the length of the oil supply passage 43 and in a condition where the flow velocity of the lubricating oil and the flow passage cross-sectional area of the oil supply passage 43 are substantially constant. Therefore, the surface area of the oil supply passage 43 is increased.

  In the present invention, as a means for increasing the flow passage surface area of the oil supply passage 43, as shown in FIGS. 5A to 5F, in the flow passage forming the oil supply passage 43, the groove 60 or This is a means for forming the protrusion 61.

  5 (a), (b), (d), and (e) are examples of forming the groove 60 in the oil supply passage 43, and FIGS. 5 (c) and 5 (f) form the protrusion 61. As an example, a plurality of grooves 60 or protrusions 61 may be formed as shown in FIGS.

  The cross-sectional shape of the flow path of the oil supply passage 43 is circular as shown in FIGS. 5 (a), (b), and (c), as shown in FIGS. 5 (d), (e), and (f). Any of a rectangle may be sufficient.

  The groove 60 or the protrusion 61 formed in the flow path of the oil supply passage 43 is desirably provided in parallel with the flow path so that no pressure loss occurs in the lubricating oil passing through the flow path.

  As a means for forming the groove 60 or the protrusion 61 in the flow path of the oil supply passage 43, the following method can be employed.

  When the casing 22a on the motor part A side is formed by a casing body and a rear cover 22d attached to the rear surface of the casing body, the rear cover 22d is attached to the casing body, and the rear cover body The lid cover 22f attached to 22e is divided into two parts, and a groove is formed on one member of the rear cover main body 22e and the lid cover 22f by casting, machining, or the like, and the groove 60 formed by this groove processing is formed on the rear cover. The oil supply passage 43 of the rear cover 22d can be formed by covering with the other member of the main body 22e and the cover cover 22f. FIG. 6 shows an example in which the groove 60 is formed in the rear cover main body 22e by groove processing.

  FIGS. 7 and 8 are examples in which a groove 60 is formed in the oil supply passage 43 of the outer diameter portion of the casing 22a on the motor portion A side by performing groove processing.

  In FIG. 7, a recess 22h into which the lid member 22g is fitted is formed in the outer diameter portion of the casing 22a on the motor part A side, and the recess 22h is grooved by casting, machining, or the like, and formed by groove machining. In this example, the groove 60 is covered with a cover member 22g.

  FIG. 8 shows that the outer diameter portion of the casing 22a on the motor portion A side is grooved by casting, machining, or the like, and the groove 60 formed by the groove processing is formed around the outer diameter portion of the casing 22a on the motor portion A side. In this example, an annular cover body 22i is fitted to the groove 60 to cover the groove 60.

  As shown in FIG. 1, the motor unit A of the in-wheel motor drive device 21 configured as described above is configured by, for example, a permanent magnet or a magnetic material that receives electromagnetic force generated by supplying an alternating current to the coil of the stator 23. The rotor 24 is rotated.

  Thereby, when the motor shaft 24a connected to the rotor 24 rotates, the curved plate 31 revolves around the rotation axis of the motor shaft 24a. At this time, the outer pin 32 engages with the curved waveform tooth shape of the curved plate 31 so as to make rolling contact, and causes the curved plate 31 to rotate in the direction opposite to the rotation of the motor shaft 24a.

  The inner pin 37 inserted through the pin hole 36 of the curved plate 31 is sufficiently thinner than the inner diameter of the pin hole 36 and abuts against the inner wall surface of the pin hole 36 as the curved plate 31 rotates. Thereby, the revolution motion of the curved plate 31 is not transmitted to the inner pin 37, and only the rotational motion of the curved plate 31 is transmitted to the wheel hub C via the output shaft 33.

  At this time, the output shaft 33 arranged coaxially with the rotation axis takes out the rotation of the curved plate 31 as the output shaft of the speed reducer B, and the rotation of the motor shaft 24a is decelerated by the speed reducer B and transmitted to the output shaft 33. Therefore, even when the low torque, high rotation type motor unit A is employed, it is possible to transmit the necessary torque to the drive wheels.

  Thus, by adopting the reduction gear B that can obtain a large reduction ratio without using a multi-stage configuration, a compact and high reduction ratio in-wheel motor drive device 21 can be obtained. Further, since the outer pin 32 is rotatable with respect to the outer pin housing 50 and the needle roller bearing 37a is provided at a position where the outer pin 32 contacts the curved plate 31, the frictional resistance is reduced. The transmission efficiency of B is improved.

  In the embodiment described above, two curved plates 31 of the speed reducer B are provided by changing the phase by 180 °. However, the number of curved plates can be arbitrarily set. For example, when three curved plates are provided. May be provided by changing the phase by 120 °.

  In the above-described embodiment, an example of a cylindrical roller bearing has been shown as the rolling bearing 34 that supports the curved plate 31. However, the present invention is not limited to this example. For example, a plain bearing, a deep groove ball bearing, a tapered roller bearing, and a needle roller Bearings, spherical roller bearings, angular contact ball bearings, 4-point contact ball bearings, etc., whether they are plain bearings or rolling bearings, regardless of whether the rolling elements are rollers or balls, All bearings can be applied, whether double row or single row. Similarly, any type of bearing can be adopted for bearings arranged in other locations.

  Moreover, in the said embodiment, the radial gap provided with the stator 23 fixed to the casing 22a in the motor part A, and the rotor 24 arrange | positioned in the position which faces the inner side of the stator 23 with a radial gap. Although the example which employ | adopted the motor was shown, the motor of arbitrary structures is applicable, without restricting to this. For example, an axial gap motor in which the stator and the rotor are arranged to face each other via a gap opened in the axial direction may be used.

  In the above-described embodiment, the oil pump 42 has shown an example in which the inner rotor 72 rotates using the rotation of the speed reducer B. However, the present invention is not limited to this, and the rotation of the rotor 24 of the motor unit A is not limited thereto. It may be an oil pump in which the inner rotor rotates, or an oil pump in which the inner rotor rotates by a separately provided electric motor.

  Furthermore, the electric vehicle equipped with the electric vehicle drive device according to the present invention may have the rear wheels as drive wheels, the front wheels as drive wheels, or a four-wheel drive vehicle. In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and should be understood as including, for example, a hybrid vehicle.

11: Electric vehicle 12: Chassis 12a: Wheel housing 12b: Suspension device 13: Front wheel 14: Drive wheel 21: In-wheel motor drive device 22: Casing 22a: Casing 22b: Casing 22c: Partition wall 22d: Rear cover 22e: Rear cover body 22f : Lid cover 22g: Lid member 22h: Recess 22i: Cover body 23: Stator 24: Rotor 24a: Motor shaft 25a: Bearing 25b: Bearing 30: Input shaft 30a: Eccentric shaft portion 30b: Eccentric shaft portion 31: Curved plate 31a : Wave profile 32: Outer pin 33: Output shaft 33a: Flange portion 33b: Shaft portion 33c: Pump drive shaft 33d: Stabilizer 34: Rolling bearing 35: Counter weight 36: Pin hole 37: Inner pin 37a: Bearing 38: Center collar 41: Oil tank 42 Oil pump 43: Oil supply passage 43a: Outer diameter portion passage 43b: Rear cover passage 44: Internal passage 44a: Oil hole 45: Internal passage 45a: Oil hole 45b: Oil hole 46: Suction passage 47: Discharge port 50: Outer pin Housing 51: Flange portion 59: Floating bolt 60: Groove 61: Protrusion 62: Fin 72: Inner rotor 72a: Tooth portion 72b: Tooth portion 73: Outer rotor 73a: Tooth portion 73b: Tooth portion 74: Pump chamber 75: Suction port 76: Discharge port 77: Pump case 81: Inner ring member 82: Outer ring member 83: Rolling element 84: Wheel mounting flange part 90: Rolling bearing 91: Rolling bearing A: Motor part B: Reduction gear C: Wheel hub

Claims (6)

  A motor unit that generates a driving force, a speed reducer that decelerates and outputs the rotation of the motor unit, and a wheel hub that transmits the output from the speed reducer to the drive wheels, and the motor unit and the speed reducer are accommodated in a casing The casing is provided with an oil supply passage through which the lubricating oil circulates by an oil pump, and the lubricating oil circulated through the oil supply passage is guided to the motor unit and the speed reducer to lubricate and cool the motor unit and the speed reducer. In the motor drive device, an in-wheel motor drive device characterized in that a groove or a protrusion is provided in the oil supply passage to increase a flow passage surface area of the oil supply passage.   The in-wheel motor drive device of Claim 1 with which the said groove | channel or protrusion is provided in parallel with the flow path of the oil supply path.   The in-wheel motor drive device according to claim 1, wherein a plurality of the grooves or protrusions are provided in a flow path of the oil supply passage.   The in-wheel motor drive device according to claim 1, wherein a cross-sectional shape of the flow path of the oil supply passage is rectangular.   The casing that accommodates the motor unit includes a casing body and a rear cover, and the rear cover is a two-piece body including a rear cover body that is attached to the casing body and a lid cover that is attached to the rear cover body, and one of the rear cover body and the lid cover. The groove is formed on the member, and the groove formed by the groove processing is covered with the other member of the rear cover main body and the lid cover, and a part of the oil supply passage is formed on the rear cover. The in-wheel motor drive device in any one of 1-4.   An outer diameter portion of a casing that accommodates the motor portion is formed by a casing body and a lid member attached to the outer diameter surface of the casing body, and either the outer diameter surface of the casing body or the inner diameter surface of the lid member is a groove. The in-wheel motor drive device according to any one of claims 1 to 5, wherein a part of the oil supply passage is formed by machining.

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